rolling road day -strange results wrong gearbox?

[CARPY25]

Newport ClubGTI held a rolling road day last saturday and the polo's that ran turned in some good if not odd results

first up was my mates GT with 106k piper induction kit and back box

max power - 85.5bhp @ 6160rpm or 84mph
max torque 107Nm @ 3990rpm or 54mph (107Nm = 78.91903lb/f)
max speed 88mph @ 6430rpm

Wheel output = 57.5
Drag = 26

then my GT with 160k k&n panel filter in a drilled air box

Max power - 88 bhp @ 6350rpm or 106mph
Max torque 104 Nm @ 3760 or 63 mph (104 Nm =76.70635lb/f)
Max speed 109 mph @6490 rpm

Wheel output = 51.5
Drag = 32.5


then my mates G40 130k toothed belts, pitstop full blend +chip ,induction kit and back box

Max power - 137 bhp @? rpm or ?mph
Max torque 180 Nm @ ? or ? mph
Max speed 104 mph @6290 rpm

Wheel output = ?
Drag = ?

will fill in the blanks later

as all the power runs were done in 4th gear this must mean i have the wrong box in my GT which might explain my 45 + mpg fuel economy


please feel free to comment


Rob

[Gareth_GT_Hatch]

yeah it sounds like your car is fitted with a 4+E from a 1.3 CL or mk2 ranger/coupe S/etc.

[CARPY25]

any idea of the gearbox code and where to find it ?


Rob

[polofresh]

your mates gt has got a top speed of only 88mph that doesnt sound right

ive got a panel filter and drilled airbox so mine should be around the same bhp as yours

[CARPY25]

your mates gt has got a top speed of only 88mph that doesnt sound right

all the power runs were in forth gear so top speed would be 100 +


Rob

[Petrified]

if you compare your speed at xx rpm with the g40, they seem the same?
so maybe you have g40 box? or more likely the g40 has a gt box and the other gt has the wrong box??

did the other gt have a 4 speed box? or a 5 speed spi box?

[CARPY25]

all the boxes were five speed been told that that the gt box is the lowest next is the g40 then the spi 13 box

if anyone has a link to the codes and where to find them on the box i'll check (when this rain stops )

to be fair my gt feels pretty quick in 1st 2nd 3rd wheel spins in second if the roads damp or if the whels ain't straight, pick up quickly from 80 in 5th but if you look that's where max torque is around 4000 revs but the best bit is the 45 mpg it returns on average


Rob

[amstrange1]

all the boxes were five speed been told that that the gt box is the lowest next is the g40 then the spi 13 box

The G40 'box (ATV code) has the longest overall gear ratios out of any of the Mk2/3 Polo 085 transmissions.

[Gareth_GT_Hatch]

either 8P or CEG, the code is located on the bit of the gearbox thats directly beneath the thermostat housing.

[CARPY25]

either 8P or CEG, the code is located on the bit of the gearbox thats directly beneath the thermostat housing.

Thanks Gareth just checked and it's CEG that means i have a cl spi box i think is it just the ratios that are different or more, it must be ok strength wise if my mates got the same box in his G40 i'll check his next time i see him


Rob

[Gareth_GT_Hatch]

pretty certain theyre all the same strength. Ive got an 8p on my gt and its fine. Got a CEG on my derby as well.

[amstrange1]

The only strength differences are the ATV, CEG and CEH 'boxes have bolt-on final drives, rather than press-on ones. So if you're running a decent amount of torque you'll run into problems quite quickly with a press-on type. Having said that, I know people who are breaking bolts...

[Tahrey1043]

lol, guess that means the CEG i put in the 1-litre will run til the end of time

is your GT an original or a conversion? or has it had the box replaced ever? seems strange that they'll sell it from the factory with the wide-spaced gearbox on when the GT was always supposed to be a close-shifting sports variant. It definitely looks like the other two have the right boxes on though
(probably either: Was an AAV, had an engine-only GT conversion; or, the original box blew, and was replaced by a "VW 5-speed" by some clueless recovery-service monkey who didn't know that gearboxes have different ratios sometimes)

does it feel like the gap between gears is a little wider than it should be, and it's bogging down slightly when going 1st-2nd, 2nd-3rd? If not then you should be able to live with it happily, and the extra second or so to 60 will pay for itself in that phenomenal sounding economy you're getting

[CARPY25]

is your GT an original or a conversion? or has it had the box replaced ever?

does it feel like the gap between gears is a little wider than it should be, and it's bogging down slightly when going 1st-2nd, 2nd-3rd? If not then you should be able to live with it happily, and the extra second or so to 60 will pay for itself in that phenomenal sounding economy you're getting

yes it's an original GT as the engine has 161k on the clock and can still put out 88bhp then it must have had a lot of work over the years so it's more than likely that someones fitted the wrong box cl spi boxes are the easest to get i think
as for the gear spacings before the rolling road i did think this was a close ratio box i'll have to drive my mates to see the difference the best bit about this box is it sits right on the peak power at between 70-80 in 5th
and last check on the mpg was 390miles for £38 thats 39.6 lts. must be 45 plus for mixed driving,if i have to change this box another CEG will be going in

Rob

[amstrange1]

I reckon it's possible you've both got GT 'boxes on your cars, but for some reason they did your power run in 5th gear. That could also explain the higher drivetrain losses seen on your motor too - your mate's car makes more power at the wheels.